Knowledge base

New technical conditions for gas networks 2026 - what changes before September 21?

26 July 2026

Clean Air Programme 2026 in Poland — July 20 changes and sizing a heat pump for the grant

Guides and articles

(46)

All (46)

Heating (12)

Pipes (7)

Units (6)

Electrical (5)

Ventilation (4)

Architecture (3)

Gas (3)

Sewerage (2)

Water Supply (2)

Installations (2)

19 July 2026

How to Design an Electrical Switchboard — a Step-by-Step Guide

A switchboard design does not start with a drawing of the enclosure — it starts with the list of circuits. That list determines how many protective…

13 June 2026

Selecting overcurrent protection — MCBs, gG fuses and RCDs step by step

Selecting the cable cross-section is only half the job — the cable still has to be protected. A poorly chosen circuit breaker or fuse means a circuit…

Architecture

11 June 2026

U-Value Heat Transfer Coefficient - Building Envelope Insulation Guide

Heating costs account for 60-70% of total residential building operating expenses. The key parameter determining the quality of building envelope…

29 May 2026

Low-pressure LPG installation — pipe sizing (propane and propane-butane mix)

An LPG (liquefied petroleum gas) installation supplied from a domestic tank or a cylinder bank is, for many homes beyond the reach of the natural gas…

11 May 2026

Pipe Water Capacity and System Water Volume — Formula, Table, Calculator

A fitter filling up the system wonders "how much glycol to pour in". A designer sizing the expansion vessel asks "what is the system water volume". A…

6 May 2026

Hydraulic Balancing of Central Heating Systems — Flows, Settings and Valve Selection

Hydraulic balancing of a central heating system means setting the flows so that each radiator, underfloor heating loop or other heat emitter receives…

24 April 2026

Mollier diagram (i-x) - how to read it and use it in HVAC design practice

For the HVAC designer, the Mollier diagram is still the fastest way to see, at a single glance, what happens to the air inside an air handling unit…

Sewerage

22 April 2026

Designing building sanitary drainage per PN-EN 12056-2

Incorrect sizing of a sanitary drainage system leads to blockages, backflow, water hammer and noise transmitted to habitable rooms — and, in extreme…

Water Supply

17 April 2026

DHW cylinder sizing with DIN 4708 — N, N_L and an example for 60 flats

The most honest preliminary method for sizing a domestic hot water cylinder in a residential building, hotel or dormitory is not a fixed number of…

14 April 2026

Building Heat Loss Calculations per EN 12831 — step-by-step guide

A heat loss balance is the foundation of every heating system design. The correct result determines boiler and heat pump sizing, radiator dimensions,…

12 April 2026

How to calculate airflow in ventilation? Standards, air change rate and calculator

Designing a ventilation system always starts with the same question - how much air must be supplied to a room and how much must be removed from it…

11 April 2026

Recuperation vs. natural ventilation - what to choose when building a house?

Ventilation is one of the key elements of every building - it affects comfort, residents' health and operating costs. In single-family houses, two…

9 April 2026

Expansion Vessel Sizing for Heating Systems — Formulas, PN-B-02414, Calculator

An expansion vessel (also called a diaphragm expansion tank) is a component without which no closed heating system can operate safely. Its role is to…

8 April 2026

Structural Design of Buried Pipes per ATV-A 127 — Designer's Guide

Designing buried pipes — sewer, water and industrial — requires a structural check, independent of hydraulic calculations. A pipe placed in a trench…

Heating media — water, glycol and dilution tables for installations

What flows in our pipes, radiators — generally in heating systems? Most often it is, of course, plain water. However, there are other fluids found in…

Gas pipe sizing - calculations, standards, and practical examples

Correct gas pipe sizing is the foundation of a safe and efficient installation. Undersized pipes cause excessive pressure drop and improper operation…

Underfloor vs Radiator Heating - Comparison, Costs and System Selection

Choosing a heating system is one of the most important decisions during the construction or renovation of a home. Underfloor heating and radiator…

Steel pipes in sanitary installations - types, standards, and applications

Steel pipes have been the foundation of sanitary, heating, and gas installations for over a hundred years. Despite the growing share of plastics…

Installations

Compressed air installation — design, calculations, and pipe sizing

Compressed air is one of the most commonly used energy carriers in industry — it is used to power pneumatic tools, control automation systems, spray…

Water Supply

Water Supply Pipe Sizing — calculations, standards and practical example

Correct pipe sizing is one of the key stages in designing an internal water supply installation. A diameter that is too small causes insufficient…

4 April 2026

Pipe diameter table for plumbing installations — steel, copper, PP, PEX, AluPEX

Selecting the correct pipe diameter is the foundation of every plumbing installation project. In practice, the designer needs to know not only the…

3 April 2026

Electrical installation power balance — a practical guide for electricians

The power balance is the foundation of every electrical installation design. Without a correct balance you cannot determine the connection capacity…

1 April 2026

Safety valve selection in heating systems – standards, calculations, practice

A safety valve is a component that a designer hopes never to think about in terms of its activation — but must always think about in terms of its…

29 March 2026

How to calculate underfloor heating step by step — a guide with calculator

Underfloor heating is one of the most popular heating systems in new construction. However, correctly calculating the installation requires…

26 March 2026

Voltage drop in electrical installations — how to calculate it and when it becomes a problem?

Every electrical cable resists the flow of current — the longer the cable and the higher the current, the more voltage is "lost" along the way. In…

Architecture

23 March 2026

Thermal Conductivity λ of Building Materials — Reference Tables

When calculating the U-value (thermal transmittance), the key parameter for each material is its thermal conductivity λ (lambda). The lower the λ…

12 March 2026

Electrical Cable Cross-Section Selection — Step-by-Step Guide According to N-SEP-E-002

Proper selection of an electrical cable cross-section is the foundation of a safe and efficient installation. A cable that is too thin risks…

11 March 2026

What Insulation Thickness for Walls, Roof and Floor? Guide with Tables

How thick does wall insulation need to be? How many centimetres of mineral wool on the roof? What thickness of XPS under the floor? These are…

8 March 2026

Ventilation Duct Sizing - Installation Designer's Guide

Proper ventilation duct sizing is one of the key stages in designing a mechanical ventilation system. A duct that is too small means excessive noise…

6 March 2026

How to Choose a Radiator? Step-by-Step Guide to Panel Radiator Selection

Radiator selection is one of the key stages in designing a central heating system. A poorly chosen radiator means either an underheated room or…

1 February 2026

Pressure Drop Calculations in Medium and High Pressure Gas Pipelines

Calculating pressure drop in medium and elevated pressure gas pipelines (0.1-16 bar) requires the application of appropriate formulas that account…

18 January 2026

Dew Point and Condensation in Building Partitions - Guide

Moisture in building partitions is one of the most serious problems in modern construction. It can lead to mold growth, degradation of insulation…

Architecture

17 January 2026

Sound Insulation of Building Partitions Rw - Guide to PN-B-02151-3 Standard

Noise in residential buildings is one of the most common problems reported by residents. According to research by the Central Statistical Office…

Installations

27 July 2025

Application for determining conditions for connection to water supply, sewage and gas networks

The procedure for obtaining connection conditions to water supply, sewage and gas networks is a key stage of any construction investment in Poland…

Sewerage

16 February 2025

Hydraulic Calculations and Pipe Sizing in Gravity Sewerage Systems

Guide to flow calculations and pipe diameter selection in gravity sewerage systems according to Polish standards Designing gravity sewerage systems…

21 October 2024

Units of Mass

Units of mass (weight) play a crucial role in everyday life and science, allowing for precise measurement of the weight of various objects. Their…

5 September 2024

Thermal Expansion in Installations and Beyond - Compensation Methods

Thermal expansion of pipes is crucial for trouble-free operation of sanitary installations, as temperature changes affect their length. In this…

17 June 2024

Unit Conversion - Real Life Stories

Units of measurement are the foundation of our civilization. They form a common language that allows us to compare distances, masses, energies, and…

6 March 2024

Control Valve Authority - Kvs Coefficient

The flow coefficient Kv (or kvs) is one of the key parameters that allows determining the optimal valve for a given hydraulic system. Valve kvs…

31 October 2023

Speed Units

Speed is a key parameter of motion, used in various fields, and speed units are an integral part of everyday life. Introduction Speed is one of the…

14 September 2023

Length Units

Length units are an integral part of our lives, allowing us to determine distances and sizes. Their history dates back thousands of years, reflecting…

2 April 2023

Volume Units

Volume units are numerical values used to describe the amount of space occupied by solids, liquids, and gases. In everyday life and science, we use…

22 March 2023

Pressure Units

Pressure is a scalar physical quantity that defines the value of force acting perpendicular to a surface divided by the size of that surface…

30 November 2022

PVC Pipes - Polyvinyl Chloride

PVC Pipes - Pipes made of this material are most commonly associated with sewage systems. And that's really the case. This is the material most…

28 November 2022

Polypropylene Pipes - PP

Polypropylene pipes - one of the most commonly chosen pipes for sanitary installations, mainly water supply systems. Relatively cheap, easy to…